Implications of long-term changes in valley geomorphology on the behavior of small-volume pyroclastic flows
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| Title: | Implications of long-term changes in valley geomorphology on the behavior of small-volume pyroclastic flows |
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| Authors: | Stinton, Adam J.1 adamstinton@yahoo.com, Sheridan, Michael F.1,2 |
| Source: | Journal of Volcanology & Geothermal Research. Sep2008, Vol. 176 Issue 1, p134-140. 7p. |
| Subjects: | Geomorphology, Terraces (Geology), Valleys, Volcanic ash, tuff, etc. |
| Geographic Terms: | Tungurahua Volcano (Ecuador), Ecuador |
| Abstract: | Abstract: Stratigraphic mapping in the lower 3km of the Vazcún Valley on the NE flank of Volcán Tungurahua (Ecuador) provides insight into the effects of long-term geomorphic changes on pyroclastic flow behavior. Exposures of deposits in the Vazcún Valley record activity over the last 2000years, during which time significant changes in the geomorphology of the valley have occurred. Two sets of terraces are present in the lower 2–3km of the valley, the older of which grades into a small debris fan at the mouth of the valley. Each terrace formed during a period of frequent activity that was separated by a long period of quiescence during which the Río Vazcún eroded a channel as deep as 40m reaching the previous base level. The pyroclastic flows from historical eruptions appear to have been largely contained within the channel that is cut through the higher terraces and debris fan. Their surface forms the lower terrace located upstream from the head of the debris fan. Thin pyroclastic deposits exposed within the city of Baños are mostly related to ash cloud surges that detached from the main flows as they slowed down within the channel. The lower reach of the present channel of the Rio Vazcún is very sinuous and deeply incised into the two sets of terraces. The winding channel would severely impede the mobility of future pyroclastic flows resulting in the deposition of thick deposits. Detachment of an overriding ash cloud surge could also occur in this region. Such a surge could be more likely to surmount the channel banks and travel over the surface of the terraces and debris for up to several kilometers from the channel. [Copyright &y& Elsevier] |
| Copyright of Journal of Volcanology & Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 34297263 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Implications of long-term changes in valley geomorphology on the behavior of small-volume pyroclastic flows – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Stinton%2C+Adam+J%2E%22">Stinton, Adam J.</searchLink><relatesTo>1</relatesTo><i> adamstinton@yahoo.com</i><br /><searchLink fieldCode="AR" term="%22Sheridan%2C+Michael+F%2E%22">Sheridan, Michael F.</searchLink><relatesTo>1,2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Volcanology+%26+Geothermal+Research%22">Journal of Volcanology & Geothermal Research</searchLink>. Sep2008, Vol. 176 Issue 1, p134-140. 7p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Geomorphology%22">Geomorphology</searchLink><br /><searchLink fieldCode="DE" term="%22Terraces+%28Geology%29%22">Terraces (Geology)</searchLink><br /><searchLink fieldCode="DE" term="%22Valleys%22">Valleys</searchLink><br /><searchLink fieldCode="DE" term="%22Volcanic+ash%2C+tuff%2C+etc%2E%22">Volcanic ash, tuff, etc.</searchLink> – Name: SubjectGeographic Label: Geographic Terms Group: Su Data: <searchLink fieldCode="DE" term="%22Tungurahua+Volcano+%28Ecuador%29%22">Tungurahua Volcano (Ecuador)</searchLink><br /><searchLink fieldCode="DE" term="%22Ecuador%22">Ecuador</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Abstract: Stratigraphic mapping in the lower 3km of the Vazcún Valley on the NE flank of Volcán Tungurahua (Ecuador) provides insight into the effects of long-term geomorphic changes on pyroclastic flow behavior. Exposures of deposits in the Vazcún Valley record activity over the last 2000years, during which time significant changes in the geomorphology of the valley have occurred. Two sets of terraces are present in the lower 2–3km of the valley, the older of which grades into a small debris fan at the mouth of the valley. Each terrace formed during a period of frequent activity that was separated by a long period of quiescence during which the Río Vazcún eroded a channel as deep as 40m reaching the previous base level. The pyroclastic flows from historical eruptions appear to have been largely contained within the channel that is cut through the higher terraces and debris fan. Their surface forms the lower terrace located upstream from the head of the debris fan. Thin pyroclastic deposits exposed within the city of Baños are mostly related to ash cloud surges that detached from the main flows as they slowed down within the channel. The lower reach of the present channel of the Rio Vazcún is very sinuous and deeply incised into the two sets of terraces. The winding channel would severely impede the mobility of future pyroclastic flows resulting in the deposition of thick deposits. Detachment of an overriding ash cloud surge could also occur in this region. Such a surge could be more likely to surmount the channel banks and travel over the surface of the terraces and debris for up to several kilometers from the channel. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Volcanology & Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jvolgeores.2008.01.010 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 7 StartPage: 134 Subjects: – SubjectFull: Geomorphology Type: general – SubjectFull: Terraces (Geology) Type: general – SubjectFull: Valleys Type: general – SubjectFull: Volcanic ash, tuff, etc. Type: general – SubjectFull: Tungurahua Volcano (Ecuador) Type: general – SubjectFull: Ecuador Type: general Titles: – TitleFull: Implications of long-term changes in valley geomorphology on the behavior of small-volume pyroclastic flows Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Stinton, Adam J. – PersonEntity: Name: NameFull: Sheridan, Michael F. IsPartOfRelationships: – BibEntity: Dates: – D: 10 M: 09 Text: Sep2008 Type: published Y: 2008 Identifiers: – Type: issn-print Value: 03770273 Numbering: – Type: volume Value: 176 – Type: issue Value: 1 Titles: – TitleFull: Journal of Volcanology & Geothermal Research Type: main |
| ResultId | 1 |
